Human Biochemistry Volume 1 - Murray R. 1993

Bioenergetics and Carbohydrate and Lipid Metabolism
Glycolysis and Pyruvate Oxidation
Biomedical Significance

Glycolysis is not only the primary pathway of glucose METABOLISM leading to the Formation of Acetyl-CoA and its oxidation in The Citric Acid Cycle, but also the main metabolic pathway for dietary FRUCTOSE AND GALACTOSE. Of particular Biomedical Significance is the ability of glycolysis to generate ATP in the absence of oxygen; this enables Skeletal Muscle to maintain high-intensity work when aerobic oxidation is insufficient, and allows Tissues with elevated glycolytic activity to remain viable during periods of oxygen deprivation. Conversely, in The Heart muscle, which is adapted to aerobic function, the capacity for glycolysis is limited, making it highly vulnerable to compromised Blood supply (ischemia). Several diseases are caused by deficiencies in glycolytic Enzymes (such as Pyruvate kinase); these conditions are characterized by hemolytic anemia. In rapidly proliferating Cancer Cells, glycolysis proceeds at a rate that far exceeds the capacity of The Citric Acid cycle. As a result, pyruvate production outpaces its consumption, leading to an excess of lactate and a localized increase in acidity within the tumor tissue—a metabolic feature sometimes exploited in the Treatment of certain types of tumors. Lactic acid levels also rise when pyruvate dehydrogenase activity is impaired.